1. Field
This invention relates generally to the field of automatic door systems and more particularly to a novel system for covering and uncovering inspection pits.
2. Prior Art
Inspection pits are widely used for a variety of purposes, including, but not limited to the automotive or trucking industry such as the facility of changing the oil, lubrication and maintenance on a vehicle, and inspection of otherwise difficult to access portions on a vehicle. Generally, such pits are located in an automotive garage or similar location, but are known to exist at virtually any location in which the above-mentioned duties are performed.
A standard inspection pit comprises a relatively long, slender, box-like cavity having a sufficient depth for an average person to stand erect. The width thereof will generally not exceed three or four feet in order to allow a standard passenger vehicle or truck to straddle the pit.
Most pits are formed of concrete or a similar building material to ensure against collapse of the cavity due to the weight of the vehicle straddling it. Steps located at one or both ends of the pit allow ingress and egress. Alternatively, some pits even have an open vertical wall adjacent to a neighboring subterranean room to provide easier access thereto.
Inspection pits are notoriously dangerous, providing a multitude of possibilities for injury to people and/or property For example, if the driver of a vehicle which is being maneuvered to straddle a pit misjudges or miscalculates the often times small clearances between the vehicle's wheels and the edges of the pit, a portion of the vehicle will fall into the pit. This can not only harm the driver, but anyone who may have been in the pit at the time of miscalculation. Furthermore, because of the vehicle's weight, generally the only way to retrieve it from the pit after it falls thereinto is to engage the services of a tow truck, which adds to the already substantial costs of repair.
Taken in another context, an inspection pit presents a potential danger to a passersby, who may be unaware of or may have momentarily forgotten about its presence. There are also those who may slip on spilled oil or trip on other obstacles in the vicinity of the pit and thereby fall into the pit.
Therefore, it becomes desirable at times to cover an inspection pit, especially when the pit is not in use or unsupervised. There are covers known in the prior art which overlay the exposed portion of a pit and these generally comprise just a solid or perforated sheet of structural steel or other similar material having sufficient structural integrity. Prior art covers, however, must be manually retracted or replaced, often requiring the services of two or more individuals. Also, the times during which the covers are moved into a desired position present an unduly high risk of an operator slipping and falling into the pit, since the covers are quite heavy and the footing precarious because of the close proximity of the pit.
Some prior art covers have the disadvantage of uncovering only a small portion of the pit at any one time. While this approach may significantly diminish the chances of accidents, it is also inconvenient since only a small portion of a vehicle can be serviced at any one time, the vehicle having to be moved before further work can be accomplished.
Prior art covers have the further disadvantage of not being equipped with warning devices which notify those in the vicinity when the covers are to be moved. Thus, when a person in the pit is unaware that the covers are being moved, he or she is in a real danger of being struck or otherwise injured.